Measure from your C7 vertebrae (the one that sticks out from your neck) down your back in a straight line to the same level as the top of your hip bones. If you're between sizes, it is better to go with the smaller of the two sizes.

Hipbelt Sizing

Men's

Small

Medium

Large

27 - 32in(67 - 80cm)

32 - 37in(81 - 94cm)

37 - 42in(92 - 105cm)

Women's

Small

Medium

Large

25 - 30in(63 - 76cm)

27 - 32in(76 - 88cm)

30 - 35in(88 - 101cm)

Hipbelt Sizing:

These sizes are based upon a measurement 2" (5cm) below the top of the hipbone resulting in 2.5 - 7.5in (6 - 9cm) of separation at the belt front.

The ultimate load carrier- for me.

Paired with my Bora 80, I believe that I 'm ready to carry just about anything I wish into the backcountry in comfort. I choose one or the other depending on the items to take; both have more capacity than their prior designs due to the kangaroo pockets, top lids and sleeping pad strap revisions.

See my review of the Bora 80 as well.. ibid for the Bora 95 with substantially more room at little weight penalty. These 2 packs just make me want to get out of town- and that says a lot when putting around 50 pounds on yourself.

I 'm told that Boras will be discontinued by Arc'teryx as of 2013. I mourn the loss for those who come after us.